1. Field of the Invention
The present invention relates to temporary coatings for teeth, that enhance their cosmetic appearance; and more particularly, to a coating comprising non-toxic components that is applied by the user.
2. Description of the Prior Art
Dentist applied procedures have long been available for improving the cosmetic appearance of teeth. Such procedures are recognized by the American Dental Association. They are typically applied at the dentist's office using commercially available preparations; and the cosmetic treatments are generally permanent. Such treatments include bleaching as discussed at http://www.ada.org/public/topics/whitening.asp using chairside bleaching procedures wherein the dentist applies a chemically oxidizing solution. The dentist may optionally use a special light or a laser light beam to activate the painted oxidizing agent. This chairside treatment takes typically 30 minutes, and several chairside procedures may be needed to achieve adequate teeth whitening. In an alternate bleaching procedure, the dentist prepares a custom fitted mouth guard that holds a bleaching gel suited for nighttime bleaching. This nighttime bleaching procedure may require repeated applications over several nights to achieve adequate teeth whitening.
Bonding techniques are commonly employed by the dentist wherein a matching tooth colored commercial preparation is applied to an etched enamel surface of the tooth to bond and cover discoloration, repair chips, breaks or cracks and fill in gaps as discussed at http://www.ada.org/public/topics/veneers.asp. With these bonding techniques a composite resin is shaped and hardened, using special ultraviolet light or chemical processes. The tooth with the hardened composite resin is smoothened and polished to appear natural. When properly applied such a bonding typically has a life expectancy of three to five years. Representative patents that disclose bonding procedures are discussed below.
Veneer is another technique used by dentists. It involves the use of a custom made shell that matches the color of the tooth, as discussed at http://www.ada.org/public/topics/veneers.asp. The veneer is fabricated by a dental technician or a commercial dental laboratory from a model provided by the dentist. Veneers are used to close gaps or cover teeth that are stained, poorly shaped or slightly crooked. Placing veneer is often an irreversible process, because small amounts of enamel are usually removed to accommodate the thickness of the veneer shell. The teeth underneath the veneer sometimes begin to decay, at which point a new replacement veneer is needed. Prior art teachings related to veneers wherein a glue or cement is used to attach a veneer and are discussed below.
U.S. Pat. No. 4,433,959 to Faunce discloses composite laminate dental veneer containing color systems. A composite laminate dental veneer is provided for attachment to the labial enamel surface of a human tooth. The dental veneer comprises an outer lamination composed of stain-resistant, chemical-resistant and erosion-resistant material, and an inner lamination composed of a material having the capability of efficient bonding to the labial enamel surface of the tooth. The inner lamination is adapted for permanent attachment to the outer lamination in such manner as to define an integral veneer mass. The laminate veneer also employs a color system embodying an additive color system which includes color pigments of an enamel blend and a subtractive color system which includes color pigments of a dentin color blend. These color pigments are distributed in color centers or microdots of color that are layered within a matrix. The veneer is glued to a prepared tooth surface. It does not form a coating applied by the user to unetched teeth.
U.S. Pat. Nos. 4,473,353, 4,822,279 to Greggs disclose a method for cosmetic restoration of anterior teeth, wherein a glazed porcelain veneer is bonded to a patient's tooth. A method and article for the cosmetic restoration of anterior teeth is provided whereby a glazed porcelain labial veneer is custom-made for a patient's tooth and thereafter chemically and mechanically bonded to such tooth, so as to provide a healthful and long-lasting cosmetic restoration of desired color, shape and esthetic appearance. This veneer is glued to a prepared tooth surface; it does not form a coating applied by user to unetched teeth.
U.S. Pat. No. 4,682,950 to Dragan discloses a device and method of bonding and veneering dental material to a tooth. An applicating device is used to cosmetically bond and veneer the teeth with composite dental material. A disposable syringe tip defines a reservoir that contains a predetermined amount of composite dental material. Connected to the syringe tip is a discharge end portion which narrows to a rectangularly shaped discharge orifice having a width of approximately 0.5 mm and a length of approximately 4 to 6 mm. The '950 patent discloses a permanent veneer of a thick strip, which is applied over surfaces of the teeth. No disclosure is contained therein concerning a temporary cosmetic coating for the teeth.
U.S. Pat. No. 4,992,049 to Weissman discloses a method for applying a veneer facing to a tooth. A veneer is secured onto a tooth substrate by a method comprising the steps of: 1) removing enamel in a matrix pattern, to a predetermined depth, from the lingual or buccal surfaces of the tooth; 2) removing the remaining outer enamel layer intermediate the matrix pattern, to the predetermined minimum depth, to provide a first, substantially level excavated enamel surface; 3) further excavating a plurality of compact areas on the first excavated enamel surface to an additional predetermined depth therebelow, but without exposing dentin, to form an indexed enamel surface; 4) taking an impression of such indexed enamel surface; and 5) obtaining from the mold a dental veneer, which can mate with such indexed excavated enamel surface and adhering the indexed veneer surface to the indexed enamel surface so as to accurately place the veneer on a tooth as an attractive outer labial or buccal surface. Preferably, the indexing grooves are undercut to improve adhesion. This veneer requires substantial preparation of tooth surface including excavation. The veneer application is permanent. It does not form a temporary cosmetic coating, which can be applied by the user.
Polymeric compositions have been proposed for use in dental applications. Representative patents disclosing such polymeric compositions are discussed below.
U.S. Pat. No. 3,066,112 to Bowen discloses dental filling material comprising vinyl silane treated fused silica and a binder consisting of BIS phenol and glycidyl acrylate. The composition has 70% of fused silica and 30% of polymer. Also disclosed are binder systems composed of the monomers, referred to in the art as BIS-GMA, admixed with other active monomers.
U.S. Pat. No. 4,097,994 to Reaville et al discloses a dental restorative composition containing glycidyl methacrylate derivative of bisphenol-A, sometimes referred to as bisphenol-A-bis-(3-methacrylato-2-hydroxypropyl) ether or, more conveniently, as oligomeric BIS-GMA resin and a ultraviolet photosensitizer, 4,4′-bis (dimethylamino) benzophenone, which also is known as Michler's ketone. Also disclosed is a dental restorative composition and tooth coating comprising the combination of an adhesive resin of the oligomeric BIS-GMA type, a low molecular weight reactive extender or diluent acrylate, an organic peroxide catalyst or free radical initiator and, as a photosensitizer, Michler's ketone. A rapidly photopolymerizable composition of the oligomeric BIS-GMA type suitable for dental restorative and tooth coating purposes is provided. Cure to a tack-free surface is obtained by the use of a particular ultraviolet sensitizer together with a peroxide catalyst. Exposure of the composition to actinic radiation produces singlet oxygen, which enters into the cross-linking reaction. However, because polymerization also takes place in the absence of oxygen, it is believed that an additional mechanism is operative. This BIS-GMA adhesive with ultraviolet sensitizer and peroxide catalyst requires UV radiation to effectively cure and harden the resin.
U.S. Pat. No. 5,407,973 to Hasegawa, et al. discloses a dental cold-polymerizing resin composition. In a powder-liquid type of dental cold-polymerizing resin composition, the powder component comprises a specific polymer such as polymethylmethacrylate containing a pyrimidinetrione derivative and an organometallic compound mixed at a specific proportion. The liquid component comprises a radical polymerizable compound containing an organic halogen compound and an aromatic tertiary amine mixed at a specific proportion used with a polymerization inhibitor.
U.S. Pat. Nos. 5,583,164 and 5,968,998 to Jochum, et al discloses dental compositions comprising bifunctional or polyfunctional acrylic-acid esters or methacrylic-acid esters. The dental compositions are based on an at least bifunctional or polyfunctional acrylic-acid and/or methacrylic-acid esters, which contain an initiator system for radical polymerization and which additionally contain a compound (1) of the general formula

in which: Ar represents aryl or substituted aryl, R1, R2 and R3 represent hydrogen, aryl or substituted aryl, straight-chain or branched chain C1-18-alkyl, C1-18-alkoxyl or C1-17-alkoxycarbonyl, in which alkyl and alkoxyl can be substituted by halogen or aryl, in which, R1 or R2, when represented by aryl or substituted aryl, C1-18-alkyl or C1-18-alkoxyl, can be linked with Ar by a single-bond and in which, Ar, when represented by phenyl, C1-18-alkylphenyl, C1-18-alkoxylphenyl, carboxyl-C1-17-alkylphenyl or halogenphenyl, R2 can be represented by —O—, which is linked with the phenyl or phenyl moiety of Ar to a benzofuran, and in which at least one of R1 to R3 represents H, and at least one of R1 to R3 represents aryl or aryl substituted by a straight-chain or branched-chain C1-18-alkyl, C1-18-alkoxyl, carboxyl-C1-17-alkyl or halogen. As a result of the content of a compound (I) the setting phase of the dental compositions is lengthened.
U.S. Pat. No. 4,310,584 to Cooper, et al. discloses multilayer light-reflecting film having a high refractive index thermoplastic polyester as the component of a system in which two or more resinous materials form a plurality of layers. A transparent thermoplastic resinous laminate film has at least 10 very thin layers of substantially uniform thickness. The layers are generally parallel, the contiguous adjacent layers are of different transparent thermoplastic resinous materials one of which is a thermoplastic polyester or copolyester resin having a refractive index of 1.55–1.61, and the adjacent resinous material has a refractive index which is lower by at least about 0.03. The contiguous adjacent layers differ in refractive index by at least about 0.03.
Representative patents disclosing application of a whitening coating to the surfaces of teeth are discussed below.
U.S. Pat. No. 4,032,627 to Suchan, et al. discloses a tooth whitening cosmetic composition. The tooth whitening covering cosmetic composition comprises Zinc Oxide, Water, Concentrated Ammonium Hydroxide and Ammonium Carbonate. It is used to form a complex system to cross-link the acrylic film forming resin Carboset Resin 514-A (B. F. Goodrich Chemical Co., of Cleveland, Ohio), which is used as a film former. After cross-linking and hardening of the resin, the free excess ammonium hydroxide is removed. Methyl cellulose (Methocel HG) is also disclosed for use as a film forming and pigment suspending agent. Ethanol is used as a solvent. The compound is said to have an extended wearing time. In practice, however, the composition is readily worn off by the abrasive action of food eaten after the compound is applied to the teeth, due to inherent softness of zinc oxide and cross-linked Carboset resin. The softness of the resin is also affected by the inability of the user to remove all the excess ammonium hydroxide following the cross-linking reaction of the Carboset Resin 514-A.
U.S. Pat. No. 4,141,144 to Lustgarten discloses a dental material and method for controlling tooth lustre. The dental material comprises a polymerizable binder, a polymerization agent and an additive comprising finely divided flakes of muscovite mica in a range of from about 1 to 20 percent by weight of the dental material for direct dental filling and restoration applications and in a range of from about 1 to 30 percent for cosmetically treating the surface of a tooth as a veneer or paint-on. The polymerizable resinous binder is 2,2-bis[4-3-methacryloxy-2-hydroxypropoxy)-phenyl]propane (BIS-GMA) with a reactive diluent; an activator and a peroxide catalyst. The use of muscovite mica provides a cosmetic treatment that is not durable due to the inherently low hardness of muscovite mica.
U.S. Pat. No. 4,512,743 to Santuchi et al. discloses a method for masking discoloration of teeth. The tooth surface is first etched with phosphoric acid to allow bonding to the composition. The polymerizable masking composition comprises liquid polymerizable acrylic monomer, a polymerization initiator for the monomer, sub-micron silica, and pigments, and is employed as a dental veneer to mask tooth discoloration. The polymerizable composition is a peroxide-catalyzed liquid difunctional acrylic ester composition comprising BIS-GMA, triethylene glycol dimethacrylate (TEGDM), fumed silica, pigments, a peroxide catalyst, and an accelerator for the catalyst. The monomer BIS-GMA is the diglycidyl dimethacrylate derivative of bisphenol-A; more precisely: 2,2-bis[4-(3-methacryloxy-2-hydroxypropoxy)phenyl]propane. The procedure is carried out in a dentist office; is not amenable to implementation by the user, since surface etching of teeth is involved. The fumed silica is extremely fine and does not reflect incident light with sufficient lustre.
U.S. Pat. No. 6,036,494 to Cohen discloses a composition and method for improving, altering, and treating teeth. The tooth is etched to create a bond with the composition, which covers discolorations or stains on the tooth's surface. The composition contains BIS-GMA polymer, an activator or catalyst such as benzoyl peroxide, and silica or titanium dioxide pigments. The tooth can be coated without etching procedure using glass ionomeric compound, which comprises pulverized fluoroaluminosilicate glass powder, carboxylic acid polymer, polymerizable unsaturated organic compound, and a polymerization catalyst. This glass ionomeric compound is light cured as discussed in Silverman E, et al., “A New Light-Cured Glass Ionomer Cement That Bonds Brackets To Teeth Without Etching In The Presence Of Saliva”. Am. Jorthod Dentofac Orthop 1995; 108:231–6. and Silverman E. et al., “Bonding Of Orthodontic Attachments Using Ultraviolet Light Polymerized Adhesives”. Buonocore M G (Ed.), “The Use Of Adhesives In Dentistry”, Charles C. Thomas, Publisher, Springfield, Ill., 1975:372–88. Both procedures require assistance of a dentist to apply the dental coating, since etching is involved in the first procedure and ultraviolet curing is needed in the second procedure. The glass ionomeric compound in these procedures is crushed fine powder of fluoroaluminosilicate glass, which is opaque and does not reflect light.
U.S. Pat. No. 6,210,163 to Cohen discloses a composition and method for cosmetically improving and altering the appearance of teeth. The teeth are first etched by the user. Weak acids such as citric acid and/or polyacrylic acid prepare the teeth surface to receive the lac based coloring compound. The lac based covering composition comprises a pigment compound selected from titanium dioxide, pulverized fluroaluminosilicate glass particles colorized by food coloring dye covered with a lac composition. This lac-based covering composition is opaque and covers stains or disclorations of the teeth. No disclosure is contained by the '163 patent concerning a composition containing a transparent glass which reflects light, thereby providing a lustrous coating for the teeth, and which can be applied to the teeth without need for etching or the like.
U.S. Pat. No. 6,652,280, to Cohen discloses a composition and method for improving, altering, and treating teeth. The teeth are first etched by the user with weak acids such as citric acid and/or polyacrylic acid, thereby preparing the teeth surfaces to receive a lac based coloring compound containing sodium fluoride to protect teeth dentin. The lac based covering composition comprises a pigment compound selected from titanium dioxide, pulverized fluroaluminosilicate glass particles colorized by food coloring dye covered with a fluoride containing lac composition. This lac based covering composition is opaque and covers stains or disclorations of the teeth. The composition does not contain a transparent glass, which reflects light, providing a lustrous coating to the teeth; it is not applied to the teeth without any etching requirement.
U.S. Pat. No. 6,652,281 to Eckhardt, et al. discloses dental materials. The dental materials contain monomers and/or prepolymers that can be subjected to a polymer-forming reaction. The dental materials comprise at least one initiating system and optionally comprise fillers, colorants, flow modifiers, stabilizers, ion-releasing substances as well as compounds which increase X-ray capacity or other modifiers. The dental materials are characterized by the presence of an initiating system proportioned such that the dental materials are sufficiently capable of flowing for at least 10 seconds after exposure to oxygen, whereupon they subsequently harden into a solid material. Polymer hardening occurs by oxidation. The dental material does not form a temporary surface coating for the teeth.
U.S. Pat. No. 6,709,271 to Yin, et al. discloses a low shrinkage dental composite, dental composite compositions, restorative compositions, and methods for their use. The compositions can contain (a) from about 1 to about 35 weight percent of a monomer portion capable of undergoing polymerization; (b) from about 75 to about 95 weight percent of a filler portion, the filler portion containing at least a spherical filler portion having at least one spherical filler particle component; and (c) from about 0.01 to about 10 weight percent of a polymerization catalyst portion capable of assisting in the polymerization and hardening of the composite. The spherical filler portion is present in an amount sufficient to reduce shrinkage of the composite after polymerization to about 1.8 percent or less. Compositions according to the invention are useful in Class I, II, IV, V, Core build-ups, and other types of dental restorations where maximum strength and polishability are desired. The spherical particles do not provide reflectivity of the incident light, and the composition is a permanent buildup composition, effected by cross-linking. It does not produce a temporary coating on the teeth surfaces.
Internet documents “Make Me Smile, Tooth Colored Fillings”, www.smiledentalcare.net/makemesmiletoothcoloredfillings.htm, and www.dochowell.com/2whitfil.htm, disclose that white fillings are made from a tooth colored plastic mixture filled with microscopic glass beads (silicon dioxide) called composite resin. Such Internet documents teach a teeth-filling composition; but do not disclose or suggest a temporary cosmetic teeth coating, especially suited for application by the user.
Notwithstanding the efforts of prior art workers to provide cosmetic improvements to the teeth, the methods and means heretofore developed require tooth etching procedures that must be performed in a dentist office and result in permanent bonding of applied materials. It would be particularly desirable if a temporary coating could be safely applied by the user, at home, in a matter of minutes, to enhance reflectivity and appearance of the teeth.